var box = document.querySelector("#fairy");
    function init(){
        var width = box.offsetWidth;
        var count = parseInt(width/10);
        for(var i=0;i<count;i++){
            var ele = document.createElement("div");
            ele.classList.add("item1");
            var size = ran(6,12)
            ele.style.width =size + "px" ;
            ele.style.height =size + "px" ;
            ele.style.top = ran(0,95) + "%";
            ele.style.left = ran(20,80) + "%";
            ele.style.animationDelay = ran(0, 30) / 10 + 's';
            box.appendChild(ele)
        }
    }
    init();
    function ran(min,max){
        return Math.floor(Math.random()*(max-min))+min;
    }